This invention relates to a spoked wheel especially for automotive vehicles; and more particularly to such a spoked wheel fabricated from sheet metal components that are welded together.
Wheels for motor vehicles are well known. Because of the need to conserve energy, it is desirable that modern wheels be made as light as possible. A lighter wheel enables a vehicle to have greater fuel economy as the energy needed to start the movement of the wheel is reduced. Also, with a lighter wheel, the suspension system of the vehicle may be made from lighter components which reduces the weight of the vehicle and thereby permits it to be driven more economically with a smaller engine.
One such light wheel that is currently being used and has become very popular because of its esthetic appeal is the formed-spoked wheel, as distinguished from a wire-spoked wheel. Although it is known to make such spoked wheels with the wheel center made from a casting or from sheet metal, the sheet metal construction has certain advantages. Sheet metal construction enables the wheel center to be made from less material, and therefore of lighter weight, than an equivalent cast wheel center. Also, spokes made from sheet metal may be welded directly to the rim of the wheel; whereas, if the wheel center is cast, a special steel insert must ordinarily be inserted at the end of the spoke before it can be welded, or the spoke is bolted to the rim. Further, since sheet metal is easier to chrome, it takes on a better chromed appearance than a casting. It should be understood that the term "wheel center" as used herein means that portion of the wheel interior of the rim.
The wheel centers of spoked wheels fabricated from sheet metal are preferably made in two portions: one portion being the hub and the other the spoked or spider portion, with the two portions being welded together. By this means, the hub and spiders may be interchanged with one another to accommodate hubs with different mounting configurations for various wheel vehicle mounting pads, and to accommodate different sized spiders for wheel rims of different diameters.
When designing the hub and spider portions of the wheel center, great care must be taken to assure that after the portions are assembled and welded together, the wheel will sustain the radial and lateral loads placed on the wheel when in service. Obviously, the performance of the wheel must be highly reliable when being used, owing to the dangerous consequences that would otherwise result. Also emphasis is placed on the esthetic appearance of the wheel so that the wheel may be commerically saleable. For this reason, it is important that the wheel not only be sturdy but also have the appearance of being sturdy. In addition, after the hub and spider are assembled, the exposed parts of the assembly must be accessible for polishing before being chromed to produce a fine chromed finish. Still further, the lug nuts should be covered behind a hub cap for ease of maintenance as well as appearance. Another important consideration in fabricating a wheel is cost. A small savings per wheel is substantial, considering the large volume of wheels ordinarily produced.
None of the known spoked wheel centers made from sheet metal are believed to offer an optimum wheel incorporating all the desirable characteristics of lightness in weight, rugged in construction, feasibility and economy of manufacture, ease of maintenance, and appearance.